Make P.gson final

Before it could be null, triggering weird issues.

src/main/java/com/massivecraft/factions/zcore/MPlugin.java

@@ -33,7 +33,7 @@ public abstract class MPlugin extends JavaPlugin {
     public PermUtil perm;
 
     // Persist related
-    public Gson gson;
+    public final Gson gson = this.getGsonBuilder().create();
     private Integer saveTask = null;
     private boolean autoSave = true;
     protected boolean loadSuccessful = false;
@@ -80,10 +80,6 @@ public abstract class MPlugin extends JavaPlugin {
         this.perm = new PermUtil(this);
         this.persist = new Persist(this);
 
-        // GSON 2.1 is now embedded in CraftBukkit, used by the auto-updater: https://github.com/Bukkit/CraftBukkit/commit/0ed1d1fdbb1e0bc09a70bc7bfdf40c1de8411665
-//		if ( ! lib.require("gson.jar", "http://search.maven.org/remotecontent?filepath=com/google/code/gson/gson/2.1/gson-2.1.jar")) return false;
-        this.gson = this.getGsonBuilder().create();
-
         this.txt = new TextUtil();
         initTXT();
 

src/main/java/com/massivecraft/factions/zcore/persist/MemoryFactions.java

@@ -13,7 +13,7 @@ import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 public abstract class MemoryFactions extends Factions {
-    public Map<String, Faction> factions = new ConcurrentHashMap<String, Faction>();
+    public final Map<String, Faction> factions = new ConcurrentHashMap<String, Faction>();
     public int nextId = 1;
 
     public void load() {

src/main/java/com/massivecraft/factions/zcore/persist/json/JSONFactions.java

@@ -22,26 +22,18 @@ import java.util.logging.Level;
 
 public class JSONFactions extends MemoryFactions {
     // Info on how to persist
-    private Gson gson;
+    private final Gson gson;
 
     public Gson getGson() {
         return gson;
     }
 
-    public void setGson(Gson gson) {
+    private final File file;
-        this.gson = gson;
-    }
-
-    private File file;
 
     public File getFile() {
         return file;
     }
 
-    public void setFile(File file) {
-        this.file = file;
-    }
-
     // -------------------------------------------- //
     // CONSTRUCTORS
     // -------------------------------------------- //